1. Technical Field
This invention relates generally to testing apparatus for video equipment and more particularly to a video test system utilizable by both consumers and technicians for generating test signals and patterns.
2. Background Art
Lower mass production costs and standardization of recording formats have greatly increased the popularity of video cassette recorders and players in the United States. Production of video recorder units in the popular VHS format exceeded 100 million units in 1986 and has been projected to exceed 150 million units by 1988. Sales of blank VHS video tape cassettes in 1985 exceeded 231 million units. What was once considered an extravagance has become common place. Not only have home video recorders been utilized for recording televised broadcasts for subsequent replay at a more convenient time but, in recent years, the popularity of utilizing video recorders and low cost video players for playback of prerecorded movies has risen phenominally. Movie studios have found unexpected benefits in releasing old films in video cassette format and video rental shops have blossomed as an industry virtually unknown five years ago.
Sources of errors have been inherent in video tape recorders and players. Errors were introduced due to head misalignment, recording or playback speed fluctuations, cables and connections and audio systems In addition, errors such as color misalignment and convergence were inherent in television receivers and monitors. Through the use of video recorders incorporate their own tuners, additional sources of errors have been introduced into the video systems. Not only was adjustment of the tuner of a television receiver required but, in addition, the video recorder tuner required precise adjustment.
Playback and recording heads eventually suffer misalignment and wear. Such wear and misalignment occured in gradual stages and was often unnoticed. Further, television receivers themselves were often misaligned due to aging and possible assembly or technician errors. Often, video recorders were employed for recording without a user first checking to determine that the tracking and other user adjustments were properly set. As a result, recordings were misaligned and suffered signal degradation.
Heretofore, adjustments for color conversion and alignment in video receivers, i.e. television sets, video monitors and video recorders and/or players required complex equipment such as signal generators including test pattern generators. Naturally, such equipment was only within the realm of persons having technical expertise and, as such, a consumer was generally not aware of adjustments which were necessary in a video system unless the system was otherwise defective, in need of service, and sent to a technician who would perform adjustments as part of other service procedures.